Optical article having a multi-component structure as an anti-theft feature and a system and method for inhibiting theft of same

ABSTRACT

A multi-component structure capable of being removably attached to a plastic element is provided. The multi-component structure includes an adhesive layer having a selectively modifiable tack strength at pre-determined locations on a first surface. The first surface is coupled to the plastic element and defining a first region. The multi-component structure further includes a backing layer coupled to the adhesive layer and defining a second region with a second surface of the adhesive layer. Upon interaction with an external stimulus the multi-component structure is configured to undergo a clean adhesive failure at the first region between the adhesive layer and the plastic element.

The present patent application is a continuation-in-part application from U.S. patent application Ser. No. 11/286,413, filed Nov. 21, 2005, the disclosure of which is hereby incorporated by reference in its entirety.

BACKGROUND

The invention relates generally to optical articles. More particularly, the invention relates to a multi-component structure employed in optical articles as an anti-theft feature and methods of making same.

Shoplifting is a major problem for retail venues and especially for shopping malls, where it is relatively difficult to keep an eye on each customer while he/she shops or moves around in the store. Relatively small objects, such as CDs and DVDs are easy targets as they can be easily hidden and carried out of the store without getting noticed. Stores, as well as the entertainment industry, incur monetary losses because of such instances. Due to the sensitive nature of the information stored inside, this problem become more severe if the CDs or DVDs are stolen from places like offices.

Even though close circuit surveillance cameras may be located at such places, shoplifting or stealing still occurs. Consumable products sometimes are equipped with theft-deterrent packaging. For example, clothing, CDs, audio tapes, DVDs and other high-value items sometimes are packaged along with tags that set off an alarm if the item is removed from the store without being purchased. These tags are engineered to detect and alert for shoplifting. For example, tags that are commonly used to secure against shoplifting are the Sensormatic® electronic article surveillance (EAS) tags based on acousto-magnetic technology. RFID tags are also employed to trace the items in store shelves and warehouses. Other theft-deteltent technologies currently used for optical discs include special hub caps for DVD packaging that lock down the DVD and prevent it from being removed from the packaging until the DVD is purchased. Similarly, “keepers” that are attached to the outside of the DVD packaging also prevent the opening of the packaging until the DVD is purchased. In some cases, retailers have resorted to storing merchandise in locked glass display cases. In other stores, the DVD cases on the shelves are empty, and the buyer receives the actual disc when the movie is purchased. Many of these approaches are unappealing in that they add an additional inconvenience to the buyer or storeowner or they are not as effective at preventing theft as desired. Optical articles, in particular, pose an additional problem in that they are very easy to remove from their packaging and the sensor/anti-theft tags may be removed easily.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a multi-component structure having an adhesive layer and a backing layer in accordance with an exemplary embodiment of the invention.

FIGS. 2 and 3 are cross-sectional views illustrating locus of failure of the multi-component structure of FIG. 1.

FIGS. 4 and 5 are cross-sectional views of the multi-component structure employing a radio frequency circuitry at two different locations in accordance with exemplary embodiments of the invention.

FIGS. 6 and 7 are cross-sectional views of the multi-component structure employing a radio frequency circuitry and a microheater at two different locations in accordance with exemplary embodiments of the invention.

FIG. 8 is a schematic flow chart illustrating the use of microheaters and radio frequency circuitry in activating a plastic element having multi-component structure in accordance with an exemplary embodiment of the invention.

FIG. 9 is a diagrammatical representation of a method for changing a functionality of an optical article in accordance with an exemplary embodiment of the invention.

FIG. 10 is a schematic view of an ID card employing a multi-component structure in accordance with an exemplary embodiment of the invention.

FIG. 11 is a perspective view of an optical article disposed inside a packaging in accordance with an exemplary embodiment of the invention.

FIG. 12 is a perspective view of an optical article disposed inside a packaging and sharing a multi-component structure with the packaging in accordance with an exemplary embodiment of the invention.

FIG. 13 is a flow chart illustrating a business method for the sale of an optical article in accordance with an exemplary embodiment of the invention.

SUMMARY

Embodiments of the invention are directed to an optical article having an anti-theft feature and a method for inhibiting theft of the same.

One exemplary embodiment of the invention is a multi-component structure capable of being removably attached to a plastic element. The multi-component structure includes an adhesive layer having a selectively modifiable tack strength at pre-determined locations on a first surface of the adhesive layer. The first surface is coupled to the plastic element to define a first region. The multi-component structure further includes a backing layer coupled to the adhesive layer to define a second region with a second surface of the adhesive layer. Upon interaction with an external stimulus the multi-component structure is configured to undergo a clean adhesive failure at the first region between the adhesive layer and the plastic element.

Another exemplary embodiment of the invention is an optical article configured to transform from a pre-activated state of functionality to an activated state of functionality. The optical article includes an optical data device for storing data. The data is read from an optical data layer in an activated state of functionality. The optical article further includes the multi-component structure.

Another exemplary embodiment of the invention is a method for selling an optical article. The method includes receiving an optical article and conducting a monetary transaction at a first location. The optical article includes an optical data layer configured to store data and a multi-component structure coupled to the optical article. The multi-component structure is configured to enable a change of functionality of the optical article from a pre-activated state to an activated state.

Another embodiment of the invention is a method for altering functionality of a plastic element from a pre-activated state to an activated state. The method includes providing a plastic element having a multi-component structure coupled to a surface of the plastic element and exposing the plastic element to an external stimulus to change a locus of failure of the multi-component structure.

These and other advantages and features will be more readily understood from the following detailed description of preferred embodiments of the invention that is provided in connection with the accompanying drawings.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

In certain embodiments, a multi-component structure is removably coupled to a plastic element. The multi-component structure may be configured to act as an anti-theft feature to inhibit the theft or unauthorized use of the plastic element such as an optical article. In the case where the optical article is a CD or a DVD, the multi-component structure is opaque to the incident laser or otherwise interferes with readout in a pre-activated state. As used herein, the term “pre-activated state” of functionality refers to a state of functionality of the optical article where the multi-component structure has not yet been exposed to one or more external stimulus as will be described in the various embodiments of the invention. In the pre-activated state, the optical article is not readable, that is, in the pre-activated state at least a portion the data on the optical data layer may not be read. In an exemplary embodiment, some or all of the portions of the optical data layer may not be read by the incident laser in the pre-activated state. For example, the multi-component structure may alter the optical property of the optical data layer in certain portions and make the data in these portions unaccessible to the incident laser. In embodiments where the data in some portions of the optical data layer is unreadable, the optical article when played in the player may result in undesirable noise or disturbances when an attempt is made to read the data from these unreadable portions, while the other portions may be read without disturbances.

Contrary to the pre-activated state, the “activated state” of functionality of the optical article refers to the state where the optical article has been exposed to one or more external stimulus as will be described with regard to various embodiments of the invention. In the activated state of functionality, the data in the optical data layer is readable. In other words, the optical article may be read without any noise or disturbances/errors, which may otherwise have been present in the pre-activated state.

The multi-component structure may be coupled to a portion of the plastic element by using an adhesive layer in the multi-component structure. Further, the adhesive layer is coupled to a backing layer. The adhesive layer may include a plurality of individual adhesive layers, which form a stack generally referred to as the adhesive layer. Similarly, the backing layer may include a plurality of individual layers, which form a stack generally referred to as the backing layer. The adhesive layer includes a first surface and a second surface. The first surface of the adhesive layer includes a selectively modifiable tack strength at pre-determined locations. As used herein, the term “selectively modifiable” refers to the ability of the adhesive layer to modify the strength of the adhesive bond. The adhesive layer may have uniform tack strength throughout. Alternatively, the adhesive layer may have variable tack strength, that is, the adhesive layer may have different tack strength at different portions of the first surface. For example, the adhesive layer may have certain portions that have higher tack strength as compared to other portions at the interface defined by the first surface. As used herein, tack strength refers to “stickiness” of the adhesive layer. The tack strength is a measurement of the strength of adhesion, typically measured using standard peel tests and reported in units of pounds-force per inch.

The first surface of the adhesive layer is coupled to the plastic element to define a first region. The second surface of the adhesive layer is coupled to the backing layer to define a second region. When the multi-component structure is de-coupled from the plastic element after interaction with an external stimulus, the multi-component structure undergoes a clean adhesive failure at the first region between the adhesive layer and the plastic element, thereby leaving no significant residue of the adhesive layer on the plastic element upon removal of the multi-component structure as seen by naked eyes. As used herein, the term “clean adhesive failure” or “clean failure” or “clean fracture” or “cleanly removed” or “clean removal” is defined as the removal of the multi-component structure from the plastic element such that no significant residue of the adhesive layer is left behind on the plastic element and the plastic element is therefore useable. For example, in embodiments where the plastic element is an optical article, “clean removal” of the multi-component structure post activation means that any minimal residue of the adhesive layer which might be left behind on the surface of the optical article, even if the adhesive residue is colored, is small enough in quantity so as to not interfere with the readability of the optical article. Whereas, when the multi-component structure is decoupled from the plastic element in the pre-activated state, that is, when the multi-component structure is decoupled from the plastic element without authorized interaction of the multi-component structure with the external stimulus, the multi-component structure undergoes a failure at the regions other than the first region. For example, in the pre-activated state the multi-component structure may undergo a failure at the second region, or a cohesive failure within the adhesive layer. The failure at regions other than the first region are not clean failures, and leave at least a portion of the multi-component structure coupled to the plastic element (e.g. adhesive residue). As will be described in detail below, this left over portion of the multi-component structure renders the plastic element unusable.

Upon exposure to the external stimulus, the multi-component structure undergoes a reduction in the adhesive bond strength at the first surface from a first adhesive bond strength in a range of at least about 1 pound-force per inch to a second adhesive bond strength of about 0 pound-force per inch up to about 1 pound-force per inch upon activation. The decrease in adhesive bond strength between the plastic element and the multi-component structure facilitates clean adhesive failure of the adhesive bond at the first surface in the activated state.

Non-limiting examples of the plastic element may include elements comprising polycarbonates, polyethylenes, polypropylenes, polyesters, polyimides, polysulfones, polyethylene terapthalate, polyamides, polyacrylates, polyurethanes, or copolymer or combinations thereof. In an exemplary embodiment, the plastic element may include an optical article. As used herein, the term “optical article” refers to an article that includes an optical data layer for storing data. The stored data may be read by, for example, an incident laser. The optical article may include one or more layers. Further, the optical article may be protected by employing a protective outer coating. The protective outer coating is transparent to the incident laser, that is, the protective outer coating allows the incident laser to pass through and reach the optical data layer.

The optical article may be an optical storage medium, such as a compact disc (CD), a digital versatile disc (DVD), multi-layer structures, such as DVD-5 or DVD-9, multi-sided structures, such as DVD-10 or DVD-18, a high definition digital versatile disc (HD-DVD), a Blu-ray disc, a near field optical storage disc, a holographic storage medium, or another like volumetric optical storage medium, such as, for example, two-photon or multi-photon absorption storage format. As will be described in detail below, if the optical article is taken out of its packaging without being authorized, or if the optical article is attempted to be played without being authorized, the multi-component structure may render the article unreadable.

In other embodiments, the optical article may also include an identification card, a passport, a payment card, a driver's license, a personal information card, or other plastic or plastic coated security documents, all of which employ an optical data layer for data storage. As will be described in detail below, in these embodiments, the multi-component structure renders the article unreadable by the reader until it is processed prior to being issued to the concerned authority. Hence, if the article is stolen before being issued, the data in the optical data layer is not readable and therefore the article is prevented from any unauthorized use before issuance.

As will be described in detail below, the multi-component structure may be in operative association with one or more devices, such that the devices may receive energy from the external stimulus in one form and convert it into another form. The converted form of energy is then transferred to the adhesive layer of the multi-component structure to change the state of functionality of the optical article. For example, the multi-component structure may be in operative association with radio frequency (RF) circuitry, which may react with an external stimulus, such as radio frequency waves, and convert it into electrical energy and/or thermal energy. The thermal energy may then be utilized by the adhesive layer to change the functionality of the optical article from the pre-activated state to the activated state. Further, the RF circuitry may include a programmable logic chip, such as in a radio frequency identification (RFID) tag. Upon exposure to the appropriate RF radiation, the RF circuitry employing, for example, a heater chip, is energized and converts the RF radiation into thermal energy. This conversion of RF energy into thermal energy creates a temperature spike of about 50° C. to about 200° C. and locally heats a specific area of the multi-component structure. In another example, one or more microheaters may be employed to heat the adhesive layer. The microheaters may be employed to heat the entire adhesive layer. Alternatively, the microheaters may be employed to heat the portions of the adhesive layer having relatively higher tack strength.

In certain embodiments, the multi-component structure may be employed to change the functionality of the optical article. The change in functionality may appear as a result of change in optical properties. The change in optical properties of the optical article can appear in any manner that results in the optical data reader system detecting a substantial change. For example, where the adhesive layer comprises a colored dye additive material, which is partially or completely opaque to a pre-determined wavelength of the optical data reader system, if the multi-component structure is removed from the optical article prior to activation thus leaving a colored residue of the adhesive layer on the surface of the optical article, there should be a significant change (e.g. reduction) in the amount of incident radiation detected as a result of selective absorption or reflection by the colored dye additive at one or more given wavelengths of interest (corresponding to the type of electronic storage device data reader system energy source). However, energy absorbance by the adhesive layer material is not the only way to effect an optical property change.

In certain embodiments, the multi-component structure may render an optical state change from the pre-activated state to the activated state. The optical change may include a change in an optical property, such as reflectivity, single layer reflectivity, dual layer reflectivity, refractive index. The multi-component structure may render the optical article partially or completely unreadable in the pre-activated state of functionality of the optical article. In the pre-activated state, the multi-component structure may act as a read-inhibit device by inhibiting the laser from reaching at least a portion of the optical data layer and reading the data on the optical data layer. For example, the multi-component structure may absorb or reflect a significant portion of the incident laser, thereby impeding it from reaching the optical data layer to read the data. If an attempt to remove the multi-component structure (e.g. peel off) from the optical article in the pre-activated state, any portion of the adhesive layer which is left on the surface of the optical article (e.g. a residue) may inhibit the laser from reaching at least a portion of the optical article.

Alternatively, the multi-component structure may render the optical article partially or completely unreadable in the pre-activated state of functionality due to the optical article being unbalanced, or otherwise have an altered mechanical property that inhibits the optical article from spinning at the correct speed within the optical drive. The multi-component structure may also prevent the optical article from physically loading into the optical drive or reader. For example, in embodiments where the optical article is a CD or a DVD, it is envisioned that the multi-component structure is disposed across the center hole of the disk (e.g. across the hub portion of the disk) thereby preventing the disk from being physically loaded into the disk-drive if the disk is in the pre-activated state. Upon removal of the multi-component structure after activation, the optical article has the appropriate mechanical properties to be loaded, spun, and read without error in the optical drive.

In an exemplary embodiment, the optical article may be made of a polycarbonate. As used herein, the term “polycarbonate” refers to both aliphatic and aromatic polycarbonates, and any co-polymers of polycarbonates incorporating structural units derived from one or more dihydroxy compounds. For example, aromatic polycarbonates marketed under the trade names LEXAN® or MAKROLON® are suitable polycarbonates.

Upon interaction with one or more external stimuli, the locus of failure of the multi-component structure is altered to change the functionality of the optical article from the pre-activated state to the activated state. As used herein, the term “locus of failure” means the physical location at which an adhesive bond breaks or fractures. For example, in the pre-activated state, the multi-component structure may be configured to have locus of failure at the second region, that is, at the interface between the adhesive layer and the backing layer. Alternatively, in the pre-activated state, the failure may also occur within the adhesive layer, which is sometimes referred to as cohesive failure. As will be described in detail with regard to FIGS. 4 and 5, in embodiments where the multi-component structure includes a radio frequency circuitry disposed within a sub-layer of the backing layer and adjacent to the adhesive layer, the locus of failure in the pre-activated state may occur within the backing between the radio frequency circuitry layer and the backing sub-layer(s). However, in the activated state, that is after interaction with the appropriate and authorized external stimulus, the locus of failure is shifted to the first region, such that when the multi-component structure is detached from the plastic element the entire multi-component structure including the adhesive layer along with the backing layer is completely and cleanly removed (e.g. peeled off) from the surface of the plastic element, thereby making the plastic element usable. For example, in the case where the plastic element is an optical article, “clean removal” of the multi-component structure, post-activated by the external stimulus, means that any residue of the adhesive layer which is left behind on the surface of the optical article, even if the adhesive residue is colored, does not interfere with the readability of the optical article.

The external stimulus may include a laser, infrared radiation, thermal energy, infrared rays, X-rays, gamma rays, microwaves, visible light, ultraviolet light, ultrasound waves, radio frequency waves, microwaves, electrical energy, chemical energy, magnetic energy, mechanical energy, or combinations thereof. Furthermore, inter-conversion between any of the above listed external stimuli (e.g. conversion of radio frequency energy first to electrical energy, and then optionally to thermal energy) is also included within the scope of this invention. The interaction of the external stimulus with the multi-component structure may include continuous, discontinuous, or pulsed forms of the external stimulus. Furthermore, the activation may be done by using a wireless stimulus (i.e. heat or electromagnetic radiation of appropriate power and wavelength such as radio waves) at the point of sale (POS) of the plastic element, which will deliver the appropriate amount of energy needed to the optical article to which the multi-component structure is disposed.

The adhesive layer may include a material having reversibly or irreversibly modifiable tack strength, that is, once altered, the tack strength may or may not be modifiable back to the initial tack strength. In one embodiment, the change from the pre-activated state to the activated state is irreversible. The decrease in tack strength at the first surface or region of the adhesive layer may be induced by a variety of mechanisms including, but not limited to, a chemical mechanism, an electrochemical mechanism, a thermal mechanism, a physical mechanism, a cross linking mechanism, or any combination thereof.

The adhesive layer may include one or more pressure sensitive adhesives materials. In at least one embodiment, the pressure sensitive adhesive is crosslinkable, that is, the pressure sensitive adhesive includes crosslinkable functionality. For example, suitable materials may include acrylate-based polymers, which contain crosslinkable functionalities. In one embodiment, the adhesive layer may include an acrylate based material that contains a glycidyl acrylate functionality, an epoxide functionality, an aziridine functionality, an ester functionality, an anhydride functionality, a carbonate functionality, or any other crosslinking functionality commonly known to one skilled in the art of polymer crosslinking.

In one embodiment the adhesive layer comprises an additive, which can induce a change in tack strength at the first surface or region of the adhesive layer. The additive may be an organic additive or an inorganic additive. For example, in one embodiment the adhesive layer comprises an expandable microsphere additive, which is designed to undergo an increase in volume when heated. Suitable microspheres include such as those marketed under the name of Expancel® Microspheres by Akzo Nobel, or those present in the dicing tapes marketed by the Nitto Denko Corporation under the trade names REVALPHA®.

The backing layer may be made of any flexible material, including but not limited to a plastic material. In one embodiment the backing material contains functionality that is capable of forming covalent bonds with the adhesive layer upon activation. The backing layer can be made of a polymeric material with a glass transition temperature (Tg) greater than about 150° C. Alternatively, the backing layer may be made of a crystalline polymer having a melting point above about 180° C. Suitable example of the backing layer material may include polycarbonates, polyethylenes, polyesters, polyimides, polysulfones, polyethylene terapthalate, polyamides, polyacrylates, polyurethanes, or copolymer or combinations thereof.

In one embodiment, the adhesive layer may include a colored dye additive material, which can absorb radiation in the visible portion of the electromagnetic spectrum (e.g. radiation with a wavelength from about 300 nm to about 900 nm), and interfere with the laser from reaching the optical data layer in the pre-activated state. In another embodiment, the material of the adhesive layer may include a convertible material that changes optical property in response to the external stimulus. For example, the material of the adhesive layer may include one or more of a color-shift dye, a photo-chromic material, a magnetic material, an electrochromic material, or a thermochromic material, a magneto-optical material, a photorefractive material, a light scattering material, a phase-change material, dye aggregates, nanoparticles, expandable microspheres, or combinations thereof. The color-shift dye may refer to a material, which may change from a first color to a second color upon interaction with an external stimulus, such that the first color, second color, or both are transparent to the incident laser. In some embodiments, the color-shift dye may include a bleachable dye, which absorbs radiation in the visible portion of the electromagnetic spectrum (e.g. radiation with a wavelength from about 300 nm to about 900 nm), but which bleaches upon interaction with the external stimulus, thereby becoming transparent to radiation in the visible portion of the electromagnetic spectrum. In one embodiment, the color-shift dye may darken upon interaction with the external stimulus, thereby absorbing the incident laser light. In another embodiment, the color-shift dye may lighten upon interaction with the external stimulus, thereby becoming transparent to the incident laser light. In yet other embodiment, the color-shift dye may include an aryl carbonium dye, thiozine, spyropyran, fulgide, diarylethene, liquid crystal, leuco dye, a hydroquinone based compound, a pH sensitive dye, a lactone dye (e.g. crystal violet lactone) or any other suitable dye chemical compounds known by one skilled in dye art. These dyes may be mixed with the adhesive material of the adhesive layer.

Furthermore, the color-shift dye, such as a photo-bleachable dye, may also be interacted with ultraviolet (UV) light. The wavelength of the UV light may be in a range from about 190 nm to about 400 nm. It should be appreciated that the wavelength of the incident laser, (i.e., the laser light used to read the optical article is about 780 nm for a CD, about 650 nm for a DVD, about 405 nm for an HD-DVD or a Blu-ray). Hence, the optical article having the photo-bleachable dye may be unreadable in pre-activated state, but becomes readable upon interaction with the external stimulus for activating the optical article. UV light may also be used when the dye is combined with photo catalytic additives, such as titania nanoparticles. Suitable but non-limiting examples include methylene blue, polymethine dye, or malachite green. These dyes may be exposed to UV light individually or in combination with activators such as titania nanoparticles. These additives may absorb the external stimulus. In an exemplary embodiment, this absorption of the external stimulus by the additives may result in temperature change of the additives. This temperature change may cause local heating of the adhesive layer thereby changing one or more properties of the adhesive layer (e.g. the tack strength of the adhesive layer) and/or affecting the color-shift dye if one is present in the adhesive layer.

The external stimulus may be selected based on the kind of material of the adhesive layer including a color-shift dye and other additives within the adhesive layer. Herein, the other additives may include organic or inorganic additives in combination with the color-shift dye. For example, the external stimulus may be thermal energy and the temperature of the thermal energy may be based upon the crosslinking rate of a polymer in the adhesive layer. In another example, when the adhesive layer includes a color-shift dye, the external stimulus may be a light source of appropriate wavelength and power to make the color-shift dye transparent to the laser, thereby changing the functionality of the optical article from an un-readable state to a readable state.

Referring now to FIG. 1, a multi-component structure 10 is coupled to a plastic element such as an optical article 12. The multi-component structure 10 includes an adhesive layer 14 having a first surface 16 and a second surface 18. The first surface 16 is coupled to the optical article 12 to define a first region 20. The second surface 18 is coupled to a backing layer 22 to define a second region 24. In the pre-activated state, the locus of failure may lie around the second region 24. Accordingly, if an attempt is made to detach the multi-component structure 10 from the optical article 12 prior to activation, the multi-component structure 10 may fail or fracture along the second region 24 leaving at least a portion of the adhesive layer 14 attached to the optical article 12, thereby making the optical article 12 unreadable by the laser. However, in the activated state, the locus of failure shifts to the first region 20.

The adhesive layer 14 may be disposed on the backing layer 22 in various forms. For example, the adhesive layer 14 may either be in the form of a continuous layer extending over the entire backing layer 22. Alternatively, the adhesive layer 14 may be a patterned layer, which may or may not extend over the entire backing layer 22. Additionally, although not illustrated, the optical article may employ two or more multi-component structures 10 disposed in discreet portions of the optical article 12.

The backing layer 22 in turn may comprise radio frequency circuitry (not shown) to receive, convert, and transfer the required energy to the adhesive layer 14 and/or the backing layer 22 as will be described in detail with regard to FIGS. 4-7. In one embodiment, the radio frequency circuitry may be disposed adjacent to the adhesive layer 14.

FIGS. 2 and 3 depict the change in the locus of failure of the multi-component structure 10 before and after the activation. As noted above, in the pre-activated state, the strength of adhesion at the second region 24 is less than the strength of adhesion at the first region 20. Accordingly, prior to activation when the multi-component structure 10 is attempted to be detached from the optical article 12, the locus of failure may occur at the second region 24. However, after activation the tack strength of the adhesive layer 14 at the second region 24 becomes greater than the tack strength at the first region 20, thereby shifting the locus of failure to the first region 20.

In one embodiment, the adhesive tack strength at the first region 20 (adhesive layer/optical article) may be reduced (e.g. from high tack strength to low tack strength) by changing the modulus of the adhesive layer 14 by crosslinking the adhesive layer, which contains materials that possess cross linkable functionalities (e.g. epoxides, aziridines, acrylates) either in the backbone of the adhesive polymer system or simply in the adhesive formulation. Upon activation at the POS, the material in the adhesive layer 14 may undergo crosslinking after being subjected to the external stimulus, thereby increasing the modulus (e.g. stiffening) of the adhesive layer 14 and decreasing the adhesion forces or tack (i.e. detackifying) at the first region 20. At the same time, if the backing layer 22 comprises sufficient functionality that can react with the crosslinking mechanism taking place in the adhesive layer 14, then upon activation, the second region 24 (interface defined by adhesive layer/backing layer) may be strengthened by forming covalent bonds across the second region 24. Therefore, upon activation, crosslinking may simultaneously decreases the strength of adhesion at the first region 20 and increases the strength of adhesion at the second region 24, thereby allowing the multi-component structure 10 to be cleanly removed from the optical article 12 and thus render the optical article 12 playable after activation. In one embodiment, in the pre-activated state the tack strength at the optical article/adhesive layer region may be at least about 1 pound-force per inch. In one embodiment, in the activated state the tack strength at the optical article/adhesive layer region may be in a range of from about 0 pound-force per inch to about 1 pound-force per inch.

FIGS. 4 to 7 illustrate alternate embodiments of the multi-component structure 10 of FIG. 1. In the illustrated embodiments of FIGS. 4 and 5, the multi-component structures employ a circuitry, such as radio frequency circuitry, to facilitate wireless energy transfer from the energy source to the multi-component structure. As illustrated in the two embodiments of FIGS. 4 and 5, the relative position of the radio frequency circuitry is variable. In the illustrated embodiments of FIGS. 6 and 7, the multi-component structures employ a radio frequency circuitry and a micro heater, where the micro heater is disposed adjacent to the adhesive layer.

FIG. 4 depicts a multi-component structure 28 disposed on the optical article 12. The multi-component structure 28 includes an adhesive layer 30 having a first surface 32 and a second surface 34. The first surface 32 is coupled to the optical article to define a first region 36. The second surface 34 is coupled to the backing layer 38 to define a second region 40. Further, the multi-component structure 28 includes a radio frequency circuitry 42 coupled to the backing layer on the side opposite to the one coupled to the adhesive layer 30. The radio frequency circuitry 42 is configured to interact with the radio frequency waves to ultimately produce thermal or electrical energy. This energy than interacts with the adhesive layer 30 and/or the backing layer 38 to alter the locus of failure of the multi-component structure 28 from the second region 40 to the first region 36. In one embodiment, the radio frequency circuitry 42 may include one or more of a microheater, two or more electrodes, and an RF antenna. The microheater may either be disposed in the same layer as the radio frequency circuitry 42 or may form a separate layer, which may be disposed adjacent to the radio frequency circuitry 42. The radio frequency circuitry 42 may convert the radio frequency waves into electrical energy. This electrical energy may then be passed on to the adhesive layer 30 via the electrodes. In another embodiment, the radio frequency circuitry 42 may include a radio frequency identification (RFID) tag. The RFID tag in its basic form includes an integrated circuit (IC) operatively coupled to an antenna, which is a small coil of wires. The data is stored in the IC, sent to the antenna, and transmitted to a reader. The RFID tag also includes a program logic chip and a capacitor.

Turning now to FIG. 5, a multi-component structure 44 having the adhesive layer 30, the backing layer 38 and the radio frequency circuitry 42 is illustrated. A first region 36 is formed between the optical article 12 and the adhesive layer 30, and a second region 46 is formed between the radio frequency circuitry 42 and the adhesive layer 30. In the pre-activated state, if the multi-component structure 44 is detached from the optical article 12, the locus of failure may either be around the second region 46 or around the region between the radio frequency circuitry 42 and the backing layer 38. However, in the activated state, the locus of failure is around the first region 36. In this embodiment, the radio frequency circuitry 42 may be disposed in a material which bonds with the backing layer 38 as well as with the adhesive layer 30 during activation at the POS, thereby making the first region 36 the weakest of all the other regions in the activated state.

FIG. 6 illustrates a multi-component structure 35 having the adhesive layer 30 and the backing layer 38. The multi-component structure 35 includes a microheater 37 embedded in a sub-layer of the backing layer 38, and a radio frequency circuitry 39 embedded in another sub-layer of the backing layer 38. The microheater 37 is in electrical communication with the radio frequency circuitry 39 and converts the electrical energy received from the radio frequency circuitry 39 into thermal energy. The thermal energy is employed to heat the adhesive layer 30 during activation of the plastic element to change the functionality of the plastic element.

FIG. 7 illustrates an alternate embodiment of the multi-component structure of FIG. 6. In the illustrated embodiment of a multi-component structure 41, the microheater 37 and the radio frequency circuitry 39 are disposed adjacent to each other. Both, the microheater 37 and the radio frequency circuitry 39 are disposed in the sub-layers of the backing layer 38 such that the microheater 37 is disposed adjacent to the adhesive layer 30 to facilitate transfer of thermal energy from the microheater 37 to the adhesive layer 30 during the activation of the plastic element.

Referring now to FIG. 8, a schematic flow chart illustrating the use of microheaters and radio frequency circuitry to alter the functionality of a plastic element is illustrated. In the illustrated embodiment, the multi-component structure (not shown) employs an adhesive layer 53 having variable tack strength. The adhesive layer 53 contains a plurality of portions 43, which have relatively higher tack strength then the rest of the other portions of the adhesive layer 53. An electronic heating circuitry 47 having a RF-resistor, for example, is disposed in the sub-layer 45 of a backing layer (not shown). The sub-layer 45 further includes microheaters 51 which are electrically coupled to the circuitry 47 by leads 49. The microheaters 51 are positioned across the sub-layer 45 in a manner that enables the microheaters 51 to at least partially superimpose on the portions 43 of the adhesive layer 53. During activation, the circuitry 47 enables the microheaters to heat the adhesive layer 53 in localized regions corresponding to the portions 43, thereby changing the tack strength of the portions 43 to enable a clean adhesive failure.

With reference to FIG. 9, a method of changing a functionality of an optical article, such as the optical storage medium 50, is illustrated. Although the illustrated method is with regard to optical storage medium 50, it should be appreciated that this method may be employed to change the functionality of other optical articles, such as an ID card, a payment card, a personal information card, flash memory card, etc., during authorization. The optical storage medium 50 includes a data storage region 52 and a non-data storage region or inner hub 54. The data storage region 52 includes an optical data layer (not shown), which stores the data, whereas the inner hub 54 is the non-data storage region of the optical storage medium 50.

The optical storage medium 50 further includes multi-component structure 56 disposed across the hub region 54. Alternatively, when disposed in or across the inner hub 54, the multi-component structure 56 may either be restricted only to the inner hub 54 or may extend out from the inner hub 54 onto the data storage region 52. Additionally, the multi-component structure 56 may be disposed in different locations in the data storage region 52 surrounding the inner hub 54. The portions 57 of the multi-component structure 56 having the adhesive layer are coupled to the medium 50, whereas the central portion 59 of the multi-component structure 56 is disposed above the hub region and may not necessarily be in direct contact with the medium 50. In an exemplary embodiment, the central portion 59 may include an antenna (not shown) for the radio frequency circuitry. The antenna interacts with the RF energy and transfers the energy to the radio frequency circuitry. The multi-component structure 56 may include any of the multi-component structures 10, 28, 44 of the previously depicted embodiments.

Further, the optical storage medium 50 may include one or more of the multi-component structure 56. The multi-component structure 56 may alter the state of functionality of the optical storage medium 50 as described above with regard to FIGS. 1-8. The method includes employing an external stimulus 58, such as a radio frequency radiation, to interact with the multi-component structure 56 to alter the locus of failure of the multi-component structure 56. During authorization, the RF circuitry of the multi-component structure 56 produces thermal energy by interacting with the RF radiation. This thermal energy then reacts with the adhesive layer (not shown) of the multi-component structure 56 and alters the locus of failure of the multi-component structure 56 to facilitate removal of the multi-component structure 56 from the optical storage medium 50, thereby providing a readable optical storage medium 50.

In alternate embodiments, the multi-component structure of the present technique may be employed in other optical articles, such as an identification (ID) card. FIG. 10 depicts a simplified structure of an identification (ID) card 60. As with the optical storage media 50, the ID card 60 includes an optical data layer 62 for storing data. The ID card 60 further includes a substrate 64 on which the optical data layer 62 is disposed. The substrate 64 may include a polycarbonate material. A capping layer 66 protects the optical data layer 62. As with the substrate 64, the capping layer 66 may also include a polycarbonate material. The capping layer 66 may be used to protect the optical data layer 62 from chemical and/or mechanical damages. The ID card 60 includes a multi-component structure 68 disposed on the capping layer 66. The multi-component structure 68 includes an adhesive layer 70 coupled to the capping layer 66 on one side and to the backing layer 72 on the other side. The backing layer 72 in turn is coupled to the radio frequency circuitry 74. In the pre-activated state, the multi-component structure 68, if peeled, leaves at least a portion of the adhesive layer 70 on the capping layer 66. The residual adhesive layer 70 on the capping layer 66 may prohibit the incident laser from reaching to the optical data layer 62 and reading the data stored therein. The multi-component structure 68 may have a flap structure 55, which facilitates removal of the multi-component structure after activation. The flap structure 55 may be integral with the multi-component structure 68 and may not contain the material of the adhesive layer 70. Although not illustrated, it should be noted that other embodiments of the multi-component structures as disclosed herein may also employ the flap structure 55.

As noted above, the material of the adhesive layer 70 may contain a colored dye additive (e.g. a material which absorbs light in the visible portion of the spectrum, 300 nm-900 nm) and may be configured to change its color to become transparent to the incident laser upon activation. However, in the activated state, after interaction with the external stimulus, the multi-component structure 68 may be peeled off along with the adhesive layer 70, thereby allowing an incident laser to pass through and reach the optical data layer 62 and allowing the reader to read the data stored in the optical data layer 62 of the card 60. The ID card 60 may be exposed to the external stimulus before issuing the ID card 60 to the concerned authority, thereby rendering the data in the optical data layer 62 readable by the incident laser. By protecting the data in this manner before issuance of the ID card 60 to the concerned authority, the undesirable use of the card may be prevented in the event the card is stolen from the location where the card was stored prior to issuance.

FIG. 11 illustrates an optical article 78, having a data storage region 80 and an inner hub 82. The optical article 78 includes a multi-component structure 84 disposed on the surface of the optical article 78. The optical article 78 is stored inside a packaging 86. The packaging 86 is configured to direct an external stimulus towards the multi-component structure 84 through a window 88 that is aligned with at least a portion of the multi-component structure 84. The window 88 is a portion of packaging that transmits or is transmissive to the external stimulus. In the illustrated embodiment, the rest of the area 90 of the packaging 86, other than the window 88, may or may not be transparent to the external stimulus, and therefore may not participate in directing the external stimulus from outside the packaging 86 towards the portion 92 of the optical article 78 having the multi-component structure 84.

Referring now to FIG. 12, the multi-component structure 77 is coupled to a portion of the optical article 78 as well as to a portion of the packaging 79. As illustrated, the label may include a microheater 81 electrically coupled to radio frequency circuitry 83. Although not illustrated, the radio frequency circuitry 83 may in turn be coupled to a power source, such as a battery. The power source may either be disposed in the multi-component structure 77, inside the packaging 79 or may be external to the packaging 79. In the illustrated embodiment, the microheater 81 at least partially superimposes a portion of the adhesive layer of the multi-component structure 77 having relatively higher tack strength. The portion of the radio frequency circuitry 83 containing the antenna does not directly superimpose the optical article 78. For example, the antenna is located in the corner of the packaging. This configuration increases the efficiency of RF power transfer to the radio frequency circuit. Accordingly, if the multi-component structure is peeled off prior to activation as shown by the arrow 85, the label leaves behind a residue 87, thereby making the optical article unreadable. However, as illustrated by the arrow 89, if the multi-component structure 77 is peeled off after activation, the multi-component structure 77 does not leave behind any residue or leaves behind a non-significant amount of residue, thereby making the optical article 78 readable.

FIG. 13 illustrates a method of transaction of an optical article having a convertible material. At block 94, an optical article having a multi-component structure is received for transaction. The transaction may be carried out at a location, such as a point-of-sale of a shop from where the optical article is being purchased, or a storage location in a working place, where the authorization of the optical article is necessitated prior to being issued to the user. It should be noted that for simplicity throughout the application the term “point-of-sale” is used to represent any location where the authorization of the optical article takes place to make it available to the user, such as a customer. At block 96, the transaction for the optical article is received. The transaction may either include a monetary transaction or verification of the user receiving the optical article. For example, at a point-of-sale of a shop, the transaction may include a monetary transaction, whereas in an office premises the transaction may include verification of the user receiving the optical article.

At block 98, the optical article is authorized for use, that is, the state of functionality of the optical article is changed from a pre-activated state to the activated state at a location, such as point-of-sale. Accordingly, if the optical article is taken without a proper transaction being conducted, the optical article will not be readable. The authorization of the optical article may be done in several ways at the authorization location. For example, the optical article may be authorized by exposing the optical article to an external stimulus having a predetermined power and emitting an energy of predetermined wavelength range by placing the optical article with or without the packaging in proximity to an external stimulus.

Further, the source for external stimulus may be built in the point of sale equipment. As used herein, the term “point of sale equipment” refers to equipment employed at the point in the shop where the sale takes place. For example, the point of sale equipment includes a bar code reader, a radio frequency identification reader, an electronic surveillance article reader, like an acousto-magnetic tag detector or de-activator, such that when the optical article or the packaging having the optical article is swiped through the bar code reader, the multi-component structure is allowed to interact with the external stimulus and the state of the optical article is converted to the activated state. Further, the source of the external stimulus may also be integrated with a hand-held wand or computer controlled boxes at the aisles. It is desirable to have sources that have a power and/or wavelength of the energy which is not commonly available, specifically to defaulting users, such as shoplifters.

Additionally, the verification of the activation may be conducted on the optical article. The verification may be desirable either to: 1) identify the defaulting users, or 2) to confirm that the optical article was accurately activated at the first point of interaction, such as a point-of-sale. In some embodiments the verification may be conducted at the second location, such as the exit point of the storage location in office premises, or a store. In these embodiments, the security system installed at the exit locations may send out signals indicating whether or not the optical article is activated. Further, a device may be installed in the security system, such that the device may interact with the multi-component structure in the optical article and make it permanently unreadable if the optical article was carried out without being activated.

EXAMPLE 1

A 1-inch by 2-inch multilayer adhesive label is affixed to a DVD by first removing the liner from the tape and pressing the adhesive layer against the read-side of a DVD. After a few hours, the adhesion of the adhesive is tested by peeling the tape away from the disc. It is found that the tape could not easily be removed from the disc. Another labeled DVD is prepared in a similar fashion using another adhesive label affixed to the disc. However, this sample is exposed to a RF source in the frequency range of about 100 KHz to about 2.5 GHz. An inductively coupled antenna located in/on the backing of the label converts the RF energy to an electric voltage. This voltage powers a micro heater located on/in the backing of the label. The micro heater locally heats the adhesive above its activation temperature of about 100° C. to about 120° C. for several seconds to reduce the adhesive strength of the adhesive layer.

EXAMPLE 2

A 5-inch long by 0.5-inch wide strip of a commercially available adhesive tape typically composed of an adhesive layer deposited on a backing layer (e.g. either a UV-activable tape form Semicorp Equipment Corporation (SEC), or a thermally-activatable tape from Nitto-Denko Corporation, was affixed to a 5-inch long by 0.5-inch wide by 0.125-inch thick piece of optical grade polycarbonate (e.g., General Electric LEXAN®) by pressing the adhesive layer evenly against the polycarbonate plastic with approximately 60 PSI of force at 50-75 degrees Celsius for 1 hour. After 1 hour, the samples were cooled to room temperature, and for a first batch of samples the strength of the adhesive bond between the tape and the polycarbonate plastic was measured using an Instron extensometer, following the protocol for a 90 degree peel test according ASTM method 6862. Peel strengths were measured at 1, 5, and 25-inches/minute peel rates. Samples from a second batch, which were prepared as described above, were further subjected to an activation step prior to peel testing. For example, the activation step was either exposure to intense UV radiation using a UV lamp obtained from Xenon Corporation or an additional heating step. Results are listed in the table below. TABLE 1 Adhesion Peel Rate Strength Adhesion for a 90 Before Strength degree Activation After Sample Peel test (pound Activation Mode of Number Tape (inch/min) force/inch) (pound force/inch) Activation 1 SEC VD-15 1 1.0 <0.1 UV - 3 seconds 2 SEC VD-15 5 1.4 <0.1 UV - 3 seconds 3 SEC VD-15 25 2.2 <0.1 UV - 3 seconds 4 SEC V-300 1 2.2 <0.1 UV - 3 seconds 5 SEC V-300 5 2.8 <0.1 UV - 3 seconds 6 SEC V-300 25 3.0 <0.1 UV - 3 seconds 7 SEC NBD-5170 1 3.3 <0.1 UV - 3 seconds 8 SEC NBD-5170 5 3.4 <0.1 UV - 3 seconds 9 SEC NBD-5170 25 6.4 <0.1 UV - 3 seconds 10 Nitto-Denko 5 2.5 <0.1 Heat (120° C. for Revalpha-3193M 3 min)

While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims. 

1. a multi-component structure capable of being removably: attached to a plastic element, comprising: an adhesive layer having a selectively modifiable tack strength at pre-determined locations on a first surface of said adhesive layer, and wherein said first surface is coupled to said plastic element and defining a first region; and a backing layer coupled to said adhesive layer and defining a second region with a second surface of said adhesive layer; wherein upon interaction with an external stimulus said multi-component structure is configured to undergo a clean adhesive failure at said first region between said adhesive layer and said plastic element.
 2. The multi-component structure of claim 1, wherein said adhesive layer comprises regions of variable tack.
 3. The multi-component structure of claim 1, wherein said backing layer comprises a plurality of individual layers.
 4. The multi-component structure of claim 1, wherein said adhesive layer comprises a colored material, which absorbs light having wavelength in a range from about 200 nm to about 900 nm.
 5. The multi-component structure of claim 1, wherein an adhesive bond strength reduces at said first region from a first adhesive bond strength of at least about 1 pound-force per inch to a second adhesive bond strength in a range of about 0 pound-force per to about 1 pound-force per at said first region upon activation.
 6. The multi-component structure of claim 1, wherein said plastic element comprises a CD, a DVD, a HD-DVD, a Blu-ray disc, a near field optical storage disc, a holographic storage medium or another like plastic optical storage medium.
 7. The multi-component structure of claim 1, wherein said plastic element comprises an identification card, a passport, a payment card, a driving license, or a personal information card.
 8. The multi-component structure of claim 1, wherein said multi-component structure alters the functionality of said plastic element upon interaction with one or more of a laser, a thermal energy, infrared rays, X-rays, gamma rays, microwaves, visible light, ultraviolet light, ultrasound waves, radio frequency waves, electrical energy, chemical energy, magnetic energy, mechanical energy, or combinations thereof.
 9. The multi-component structure of claim 1, wherein said adhesive layer further comprises a color-shift dye, a photo-chromic material, a magnetic material, an electrochromic material, or a thermochromic material, a magneto-optical material, a photorefractive material, a light scattering material, a phase-change material, dye aggregates, nanoparticles, expandable micro-spheres, or combinations thereof.
 10. The multi-component structure of claim 1, wherein said adhesive layer comprises a pressure sensitive adhesive.
 11. The multi-component structure of claim 10, wherein said pressure sensitive adhesive comprises a crosslinking functionality.
 12. The multi-component structure of claim 11, wherein said pressure sensitive adhesive comprises an acrylate containing polymer, an epoxy, a silicone containing polymer, combinations thereof.
 13. The multi-component structure of claim 10, wherein said pressure sensitive adhesive comprises additives selected from the group consisting of a color-shift dye, a photo-chromic material, a magnetic material, an electrochromic material, or a thermochromic material, a magneto-optical material, a photorefractive material, a light scattering material, a phase-change material, dye aggregates, nanoparticles, expandable microspheres, or combinations thereof.
 14. The multi-component structure of claim 1, wherein said adhesive layer comprises an adhesive in which an adhesive bond strength decreases at said first region upon exposure to ultraviolet light, thermal energy, an electric current, or combinations thereof.
 15. The multi-component structure of claim 1, further comprising radio frequency circuitry.
 16. The multi-component structure of claim 15, wherein said radio frequency circuitry is disposed in a sub-layer of said backing layer.
 17. The multi-component structure of claim 15, wherein said radio frequency circuitry is disposed adjacent said adhesive layer.
 18. The multi-component structure of claim 15, further comprising a microheater, microelectrodes, a radio frequency antenna, or combinations thereof.
 19. The multi-component structure of claim 1, further comprising a packaging for said plastic element, wherein said packaging enables an external stimulus to be directed toward at least a portion of said multi-component structure.
 20. The multi-component structure of claim 19, wherein said packaging comprises a window aligned with at least a portion of said multi-component structure.
 21. The multi-component structure of claim 19, wherein said packaging comprises power source in electric communication with said multi-component structure.
 22. An optical article configured to transform from a pre-activated state of functionality to an activated state of functionality, comprising: an optical data layer for storing data, wherein said data is read from said optical data layer in an activated state of functionality; and a multi-component structure removably attached to said optical data layer, said multi-component structure comprising: an adhesive layer having a first surface and a second surface, said adhesive layer having a selectively modifiable tack strength at pre-determined locations on said first surface, and wherein said first surface is coupled to said optical data device to define a first region; and a backing layer coupled to said second surface of said adhesive layer and defining a second region with said second surface of said adhesive layer; wherein after interaction with an external stimulus, said multi-component structure is configured to undergo a clean adhesive failure at said first region to alter the functionality of the optical article from a pre-activated state to said activated state.
 23. The optical article of claim 22, wherein said multi-component structure is configured to undergo a clean adhesive failure at said second region prior to interaction of multi-component structure with said determined external stimulus.
 24. The optical article of claim 22, wherein said multi-component structure further comprising a radio frequency circuitry in operative association with said adhesive layer and said backing layer, wherein said radio frequency circuitry is configured to interact with said external stimulus for generating a thermal response, an electrical response, or both.
 25. The optical article of claim 24, wherein said radio frequency circuitry is disposed adjacent to said adhesive layer
 26. The optical article of claim 24, wherein said radio frequency circuitry is disposed adjacent to said backing layer.
 27. A method for selling an optical article, comprising: receiving an optical article, comprising: an optical data layer configured to store data; a multi-component structure coupled to the optical article, the multi-component structure being configured to enable a change of functionality of the optical article from a pre-activated state to an activated state; and conducting a monetary transaction at a first location.
 28. The method of claim 27, further comprising: authorizing the optical article for use, comprising: interacting the multi-component structure to an external stimulus, wherein said interaction renders a change in the optical article from the pre-activated state to the activated state.
 29. The method of claim 28, further comprising verifying the authorization of the optical article.
 30. The method of claim 27, wherein the step of verifying is conducted at a second location.
 31. The method of claim 27, further comprising providing a source for the external stimulus.
 32. The method of claim 31, wherein the source comprises a thermal source, an electrical source, an ultrasound source, a light source, an X-ray source, a gamma source, microwave source, a radio frequency source, or combinations thereof.
 33. The method of claim 31, wherein the source for the external stimulus is embedded in a point of sale equipment.
 34. A method for altering functionality of a plastic element from a pre-activated state to an activated state, comprising: providing a plastic element having a multi-component structure coupled to a surface of the plastic element; and exposing the plastic element to an external stimulus to change a locus of failure of the multi-component structure. 